1 /**
2 * @file system_max32660.c
3 * @brief System-level initialization implementation file
4 */
5
6 /******************************************************************************
7 *
8 * Copyright (C) 2022-2023 Maxim Integrated Products, Inc. (now owned by
9 * Analog Devices, Inc.),
10 * Copyright (C) 2023-2024 Analog Devices, Inc.
11 *
12 * Licensed under the Apache License, Version 2.0 (the "License");
13 * you may not use this file except in compliance with the License.
14 * You may obtain a copy of the License at
15 *
16 * http://www.apache.org/licenses/LICENSE-2.0
17 *
18 * Unless required by applicable law or agreed to in writing, software
19 * distributed under the License is distributed on an "AS IS" BASIS,
20 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
21 * See the License for the specific language governing permissions and
22 * limitations under the License.
23 *
24 ******************************************************************************/
25
26 #include <string.h>
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include "max32660.h"
30 #include "gcr_regs.h"
31 #include "pwrseq_regs.h"
32 #include "tmr_regs.h"
33 #include "wdt_regs.h"
34 #include "mxc_sys.h"
35
36 extern void (*const __isr_vector[])(void);
37 uint32_t SystemCoreClock = HIRC96_FREQ;
38
39 /*
40 The libc implementation from GCC 11+ depends on _getpid and _kill in some places.
41 There is no concept of processes/PIDs in the baremetal PeriphDrivers, therefore
42 we implement stub functions that return an error code to resolve linker warnings.
43 */
_getpid(void)44 __weak int _getpid(void)
45 {
46 return E_NOT_SUPPORTED;
47 }
48
_kill(void)49 __weak int _kill(void)
50 {
51 return E_NOT_SUPPORTED;
52 }
53
SystemCoreClockUpdate(void)54 __weak void SystemCoreClockUpdate(void)
55 {
56 uint32_t base_freq, div, clk_src, ovr;
57
58 // Get the clock source and frequency
59 clk_src = (MXC_GCR->clk_ctrl & MXC_F_GCR_CLK_CTRL_CLKSEL);
60
61 if (clk_src == MXC_S_GCR_CLK_CTRL_CLKSEL_HFXIN) {
62 base_freq = HFX_FREQ;
63 } else {
64 if (clk_src == MXC_S_GCR_CLK_CTRL_CLKSEL_NANORING) {
65 base_freq = NANORING_FREQ;
66 } else {
67 ovr = (MXC_PWRSEQ->lp_ctrl & MXC_F_PWRSEQ_LP_CTRL_OVR);
68 if (ovr == MXC_S_PWRSEQ_LP_CTRL_OVR_0_9V) {
69 base_freq = HIRC96_FREQ / 4;
70 } else {
71 if (ovr == MXC_S_PWRSEQ_LP_CTRL_OVR_1_0V) {
72 base_freq = HIRC96_FREQ / 2;
73 } else {
74 base_freq = HIRC96_FREQ;
75 }
76 }
77 }
78 }
79
80 // Get the clock divider
81 div = (MXC_GCR->clk_ctrl & MXC_F_GCR_CLK_CTRL_PSC) >> MXC_F_GCR_CLK_CTRL_PSC_POS;
82
83 SystemCoreClock = base_freq >> div;
84 }
85
86 /* This function is called before C runtime initialization and can be
87 * implemented by the application for early initializations. If a value other
88 * than '0' is returned, the C runtime initialization will be skipped.
89 *
90 * You may over-ride this function in your program by defining a custom
91 * PreInit(), but care should be taken to reproduce the initilization steps
92 * or a non-functional system may result.
93 */
PreInit(void)94 __weak int PreInit(void)
95 {
96 /* Do nothing */
97 return 0;
98 }
99
100 /* This function can be implemented by the application to initialize the board */
Board_Init(void)101 __weak int Board_Init(void)
102 {
103 /* Do nothing */
104 return 0;
105 }
106
107 /* This function is called just before control is transferred to main().
108 *
109 * You may over-ride this function in your program by defining a custom
110 * SystemInit(), but care should be taken to reproduce the initialization
111 * steps or a non-functional system may result.
112 */
SystemInit(void)113 __weak void SystemInit(void)
114 {
115 /* Configure the interrupt controller to use the application vector table in */
116 /* the application space */
117 /* IAR & Keil must set vector table after all memory initialization. */
118 SCB->VTOR = (uint32_t)__isr_vector;
119
120 MXC_WDT0->ctrl &=
121 ~MXC_F_WDT_CTRL_WDT_EN; /* Turn off watchdog. Application can re-enable as needed. */
122
123 /* Enable FPU on Cortex-M4, which occupies coprocessor slots 10 & 11 */
124 /* Grant full access, per "Table B3-24 CPACR bit assignments". */
125 /* DDI0403D "ARMv7-M Architecture Reference Manual" */
126 SCB->CPACR |= SCB_CPACR_CP10_Msk | SCB_CPACR_CP11_Msk;
127 __DSB();
128 __ISB();
129
130 /* Switch system clock to HIRC */
131 MXC_SYS_Clock_Select(MXC_SYS_CLOCK_HIRC);
132
133 /* Disable clocks to peripherals by default to reduce power */
134 MXC_SYS_ClockDisable(MXC_SYS_PERIPH_CLOCK_DMA);
135 MXC_SYS_ClockDisable(MXC_SYS_PERIPH_CLOCK_SPI0);
136 MXC_SYS_ClockDisable(MXC_SYS_PERIPH_CLOCK_SPI1);
137 MXC_SYS_ClockDisable(MXC_SYS_PERIPH_CLOCK_UART0);
138 MXC_SYS_ClockDisable(MXC_SYS_PERIPH_CLOCK_UART1);
139 MXC_SYS_ClockDisable(MXC_SYS_PERIPH_CLOCK_I2C0);
140 MXC_SYS_ClockDisable(MXC_SYS_PERIPH_CLOCK_TMR0);
141 MXC_SYS_ClockDisable(MXC_SYS_PERIPH_CLOCK_TMR1);
142 MXC_SYS_ClockDisable(MXC_SYS_PERIPH_CLOCK_TMR2);
143 MXC_SYS_ClockDisable(MXC_SYS_PERIPH_CLOCK_I2C1);
144
145 Board_Init();
146 }
147
148 #if defined(__CC_ARM)
149 /* Global variable initialization does not occur until post scatterload in Keil tools.*/
150
151 /* External function called after our post scatterload function implementation. */
152 extern void $Super$$__main_after_scatterload(void);
153
154 /**
155 * @brief Initialization function for SystemCoreClock and Board_Init.
156 * @details $Sub$$__main_after_scatterload is called during system startup in the Keil
157 * toolset. Global variable and static variable space must be set up by the compiler
158 * prior to using these memory spaces. Setting up the SystemCoreClock and Board_Init
159 * require global memory for variable storage and are called from this function in
160 * the Keil tool chain.
161 */
$Sub$$__main_after_scatterload(void)162 void $Sub$$__main_after_scatterload(void)
163 {
164 SystemInit();
165 $Super$$__main_after_scatterload();
166 }
167 #endif /* __CC_ARM */
168
